I was at the Hay festival earlier this month when the hunt launched to find the "Puffin of Puffins". Celebrating 70 years of existence, the publisher picked seven "modern classics" – Eve Garnett's The Family from One End Street (1940s), EB White's Charlotte's Web (50s), Clive King's Stig of the Dump (60s), Roald Dahl's Charlie and the Chocolate Factory (70s), Michelle Magorian's Goodnight Mister Tom (80s), Jeremy Strong's The Hundred-Mile-an-Hour Dog (90s) and Eoin Colfer's Artemis Fowl (00s) – and opened them up to a public vote.

Given that Artemis Fowl (against which I have nothing, other than it's not my own personal favourite Puffin) received 68% of the vote, I think we can safely assume the voters were largely children. It's a mega-bestseller, and the rest of the titles were possibly seen as boring old books their parents would like them to read – people with children, correct me if I'm wrong. As children's author and television presenter Jason Bradbury, championing the Colfer at Hay, pointed out to that audience, "it's actually a book released in your lifetimes, children"; Puffin's managing director, Francesca Dow, said today that the novel is "very much a book for the 21st century" – as opposed to the others, I suppose, which are very much for the 20th.

But author Cathy Cassidy's vehement support for the Magorian title – "I'd never read a book before that pushed the boundaries … and made me cry so much" – reminded me of how much I'd loved Goodnight Mister Tom as a child. At my parents' house the weekend after Hay, I tracked it down and reread it, and oh my goodness, it was just as wonderful. Evacuee Will, "thin and sickly looking, pale with limp sandy hair and dull grey eyes", is slowly turned into a bouncing, robust country boy by the gruff but tender administrations of Mister Tom (who sparks back to life himself as he cares for the abused Will). The colourful, excitable Zach, Will's first friend – "Wizzo!" – is as charming as he ever was. The tragedy of Will's forced return to his mentally unstable mother in a London at war is still as horrendously upsetting, the heartbreak which follows his return to Mister Tom's so carefully, thoughtfully, believably played out.

As Cassidy said, "I didn't realise we were allowed to do things like that in children's books." You almost can't quite believe Magorian is going to go through with her storyline, and then she does, and then you – well, I at least – cry lots.

I also adored Magorian's Back Home, another story of an evacuee. Rusty is sent to America, and the drama plays out around her return to England to a world and a family who feel like strangers. Anyone else remember that one? I loved the bit where Rusty escapes from boarding school to decorate her own little cabin in the woods.

But Goodnight Mister Tom is better. It should have been the Puffin of Puffins, and I think it has a good claim to be the children's book of children's books. (Now that'd be a fun vote, although we may have to exclude anything published after I graduated to grown-up books, else I'll only get upset again.) I'm imagining that all you discerning adult readers will agree with me about Goodnight Mister Tom being the top Puffin – but please let me know either way. And I'll try not to cry if you disagree.